Polynitro-nitramine polymers and method of preparing same



3,40,99 Patented June 19, 1962 inert solvent is utilized in our process,long chain poly- PO R NIT 3,040,099 PGLYMERS A mers are produced, wherea mixture of a completely N11 RAMINE inert solvent and a small amount ofa slightly reactive METHOD OF PREPARING SAME solvent is utilized, apolymer having an intermediate chain Henry Feuer West Lafayette Ind. andRobert Miller East Pater son, N.J., assighors lo Purdue Research lengthWm be formed and Where a Short Polymer 18 Foundation, Lafayette, Ind, acorporation of Indiana desifedfhfi ent re solvent medium is slight yreactive. Of N Drawing Filed 24 195 Sen 33 49 course t is obvious thatthe terminal radicals of our poly- 1 Cl im, (Cl, 260-584.) mers willvary according to the solvent and it is possible to make polymers havingunlike terminal radicals by Our invention relates to polynitro-nitraminepolymers using a solvent medium composed of a mixture of two and moreparticularly, it relates to the production of polyor more slightlyreactive solvents. nitro-nitramine polymers by the reaction ofZ-nitroalkyl Our reaction for the production of long chain polyd-iesterswith the salt of a primary aliphatic or aromatic nitro-nitraminepolymers from 2-nitroa1kyl diesters and polynitramine in the presence ofa weak base. the salts of polynitramines in the presence of Weak baseThe polynitro-nitramine polymers produced in accordis effected insolvents totally inert to the reactants and once with our invention havethe following structural totally inert to the resultingpolynitro-nitramine polymers, fo mula; as for example, tetrahydrofuran,dirnethylsulfoxide, di-

NO: NO: N02 1702 1Y0: IITOz RCHz( 7CH2l:OHz--CHy-Ih-OH2-CHN-OH=-C-Cl1r:|CH2OCH,R-

l R R n R wherein R is hydroxy, methoxy, or tertiary butoxy; R isacylalkyl amides, such as dimethylformamide, dimethylhydrogen orhydroxymethyl; and n is an integer ranging acetamide, etc.;hydrocarbons, such as hexane, octane, from 25 toluene, xylene;thioethers, such as dirnethyl sulfide, di-

The nitroesters which we employ in our process have the ethylsulfide,etc; chlorinated hydrocarbons, such as f ll i Structural f lcarbontetrachloride, chloroform, etc; ethers, such as di- No N02ethylether, dimethylether, methylphenylether, etc.

| I When it is desired to form a short chain polymer, such XO-CII(IJ Cas 1,26 dimethoxy-7,10,17,20-tetraaza-2,5,7,10,12,15,17 2 E 3 n H 220,22,25-decanitrohexacosane, a slightly reactive solvent Where X is isutilized and the terminal radical of the polymer will be taken from thesolvent molecule. Examples of slightly if reactive solvents includewater; alcohols, such as methanol,

. ..Q-Y, -s01Y, -SO H, NH2, s t ethanol, etc; thioalcohols such asmethylmercaptan,

Y is hydrogen, alkyl having up to ten carbon atoms or ethylmercaptan,etc; nitropanafiins, such as nitromethane,

aryl. Examples of 2-nitroalkyl esters which we may emdrnitrom'ethane,nitroethane, tetranitroethane, l-nitroploy include: 1,6 g,5dinitrohexane, 1,7-dipropane, etc.; nitroalcohols, such as nitroethanol,2,2-diacetoxy-1,7-diphenyl-2,6-dinitroheptane, 1,6 diheptoxy- P P1,6-diPlIenyl2,5-dinitro3,3,4,4-tetrafiuorohexane, 1,10-di- 40 T e chainlength of our polymers can also be varied acetoXy-2,9-dinitro-decane,1,5 diacetoxy 2,4 -dinitroby the utilization of sterically hinderedslightly reactive 3,3 difluoropentane, 2,6 diacetoxy 3,5-dinitroheptane,Solvents t-blltyllalcohoL -butylmercaptan, etc. 8,18 diacetoxy-9,17dinitro 8,18 diheptylpentacosane, The utrlrzatron of slightly reactivesolvents to terminate 3,11-diacetoxy 3,11dimethyl-4,l0-dinitro-5,5,6,6,7,7 polymenchains is quite important forit provides a means 8,8,9,9 decafiuorotridecane; 1,10(2,9-dinitrodecyl)diof bonding P l t0 the reaction motor Case yphosphate, 1,5 dinitrato-2,4-dinitro-3,3-difluoropentane, COHVfiTSiOIl aCross-linked P y y treatment With 1,6 disulfato 2,5-dinitrohexane and1,7-diformato-l,7- a small amount of diisocyanate or dicarboxylicaciddiphenyl-Z,G-dinitroheptane, etc. Our compounds are solids. As such,they are solid In preparing our l i i i polymers, we propellants forreact1on motors. These polymers are act zmitroalkyl diesters in hPresence f a k b stable to shock, heat, etc. to the extent that, as ageneral with the salts of aliphatic or aromatic nitramines having rule,additional stabilizers are not required for the propelthe followinggeneral formula: 1am mlXtures.

NO R1 NO Monomers prepared by the process of our invention are H 2 I HPIaStlCIZEIS for mtropolymers formed by the process of N-O-N Mm++ ourinvention. These propellants can be dissolved in j polar solvents, suchas dimethylformamide and lower nitro alkanes such as tetranitromethane,and, as they are genwhere M 15 2} metal i011 h h from the grohhcohslshhg erally fuel rich, can be utilized as a fuel in the process ofof the alkali metals and ahiahhe Pi mhtalsi 15 US. Patent No. 2,537,526where tetranitromethane and the mteger We Prefer to utlhze a mtr'amme were hexanitroethane were used as oxidants and liquid nitro- "1 15 assoluble hhear Polymers are formed from parafiins, such as nitroethane,l-nitropropane, 2-nitroprothese nitramines Whelfleasinsolbletvsrosslinked polymers pane, etc., were used as fuels; in theprocesses described are famed where h f t in US. Patents Nos. 2,582,048and 2,548,803 wherein The Weak bases whlc can 6 use m carrymg nitrosubstituted aliphatic compounds having more than our process for theproduction of polynitro-nitramine polymers include carbonates,bicarbonates, sulfites, phosphates, borates, etc; hydroxides such as,for example, sodium hydroxide, potassium hydroxide, calcium hydroxide,barium hydroxide, etc.; esters such as sodium one nitro group per carbonatom were used as oxidants and nitro substituted compounds having lessthan one nitro group per carbon atom were used as fuels inmonopropellant systems; or in the similar process of US. Patent No.acetate, sodium propionate, potassium acetate, barium 2,590,009- othersolvents which can he used f liquify acetate, etc. our polymers rncludehydrazine, lower alkyl amines, d1-

The type of solvent utilized in our process determines methyl sulfoxide,Cellosolve, acetorutrlle, lower alkanols, the chain length of thepolymers. Where a completely lower nitro esters, and lower nitro ethers.

- Ourpolymers can be mixed with various oxidant salts, I I

such as ammonium nitrate, ammonium perchlorate, I

lithiumperchlorate, etc. to obtain solid heterogeneous I propellantshaving specific. impulses on'the order of that The following examplesare offered to fur of Ballistite. therillustrate our invention; however,we do not intend to be limited to the specific proportions,materials,'or con- 7 ditions employed, but rather we intend toincludewithin the scope of our invention all equivalents obvious tothose skilled in the art.

Example I To a 300 ml. three necked flask, equipped with'aconi denser,thermometer and mechanical stirrer, containing 1.64 g. (0.04 mole)- of97% assay sodium hydroxide and 3.28 g. (0.04 mole) of anhydrous sodiumacetate dissolved in a mixture of 50 ml. of water'and 150 fill/Ofdimethyl sulfoxideat -5", was added 3.0 g. (0.02 mole) .of ethylenedinitramine. After salt formation was complete, 5.84 g.

. (0.02 mole) of 1,6-diacetoxy-2,5*dinitrohexane was added all at once.I The reaction was maintained. at 0-5 for fifteen minutesand then.allowed to come to room temperature slowly. After being stirredapproximately one hour at room temperature, the reaction mixture was3.28 (0.04 mole) of sodium acetate dissolved in a mixture of 20 ml.'ofwater'and 230 ml. of methanol at 0-5, was

' added 3.0 (0.02 mole) of ethylene dinitramine. After salt formationwas complete, 5.84 g. (0.02 mole). of 1,6}

diacetoxy-2,5-dinitrohexane was added at .05. The

reaction mixture was held at this temperature for minutes, and thenallowed to corne'to room temperature'sl'owly, and maintainedthere with awater bath for four hours.

.by pouring the mixture into a large excess of water with vigorousstirring. The product obtained on filtration was again washed aspreviously described, and yielded 4.5 g.

. of product. An infrared spectrum of this material re vealed theexpected ether band at 9 u.

' Analysis.-Calcu1ated for C H O N C, 32.72; H, 5.00; N, 22.27. Found:C, 33.46; H, 4.48; N, 22.00.

Example 11 In a 125 ml. Erlenmeyer flask, containing 30 ml. of dimethylsulfoxide and 1 drop of 10% aqueous sodium hydroxide solution wasdissolved 1.0 g. of 1,26-dirnethoxy-7,10,l7,20tetraaza-2,5,7,10,l2,15,17,20,22,25 deeanitro hexacosane. Tothis mixture was added 4 ml. of 37% formalin solution with agitation.The reaction flask was then stoppered and allowed to stand at roomtemperature (24-26) for 40 hours. At the end of this time 1.5 ml. ofglacial acetic acid was added to the mixture. The mixture was thenpoured into 400 ml. of water with vigorous agitation and the materialwhich precipitated was filtered and washed with several portions ofwater, 95% ethanol, and ethyl ether, in that order. The1,26-dimethoxy-2,5, 12,15,22,25-hexa(hydroxymethyl)-7,10,17,20tetraaza-Z, 5,7,10,12,15,17,20,22,25 decanitrohexacosane thus obtained,weighed 0.85 g. and had an explosion point at 188. This material waspurified by dissolving it in a minimum amount of dimethyl sulfoxidecontaining 2% glacial acetic acid, and then pouring this mixture into alarge excess of water with vigorous stirring. The material whichprecipitated was filtered and washed as previously described.

Analysis-Calculated for C H O N C, 33.96; H, 5.28; N, 18.49. Found: C,35.12; H, 5.05; N, 18.55.

Example 111 To a 300 ml. three-necked flask, equipped with acoudcnser,thermometer and mechanical stirrer, contairung 1.64 g. (0.04 mole) of97% assay sodium hydroxide and heated to 39-40 for 15 hours. At the endof this time, (no reaction mixture was filtered through a sintered glassfunnel. and the filtrate was poured withvigorous stirring into 700 ml.of water. The precipitate that formed was allowed to settle and was thenfiltered. The, 1,16-dihydroxy-7,10-diaza 2,5,7,10,12,l5hexanitrohexadecane was washed with several portions of water, 95%ethanol, and ethyl ether, in that order.

was dried in vacuum to yield 3.83 g. of product, This material did notmelt on heatingbut exploded at-183".

The product was purified by dissolving it in a minimum amount ofdimethyl sulfoxide containing 2% glacial acetic acid, and pouring themixture with vigorous stirring into. excess water.

I The resulting precipitate was filtered and washed as previouslydescribed.

- .Analysis.-Calculated r01 c,.,H ,o,,N,; c 31.70; H,

4.91; 2 1.13.' Found: c, 3300,11; 4.33.; N, 20.90.

Example IV In a 500 ml. three-necked round bottom fiaskfitted with amechanical stirrer, thermometer, and refluxcondenser with drying tubewere placed 1.64 g. (0.04 mole) 97% assay sodium hydroxide, 3.28 g.(0.04 mole) sodium acetate, and ml. water. Thesolutionwas cooled to 05and 3.0.g.-(0.02- mole) ethylene dinitramine was added with 5 ml. water.When the salt had formed, as indicated by a clear solution and pH 9-9.5,225 ml. t-butyl alcohol, 30 ml.- dimethyl sulfoxide, and. 5.84 g. (0.02mole) 1,6-diaeetoxy2,5-dinitrohexane were added to. the

The reaction mixture was stirred for 70' cold solution. minutes in anice-water bath. The ice was then removed, and the temperature rose to 28in 4% hours. The mixture was then heated to 42-43 for 17 hours andfiltered. The solid was washed with water and dried in vacuo. The yieldof polymeric material amounted to 5.73 g. It was partially dissolved indimethyl formamide containing 2% glacial acetic acid, filtered andpoured with vigorous stirring into an excess of water. The resultingprecipitate was filtered through a sintered glass funnel and washed withwater, ethanol, and ether, then dried in air. It was redissolved asabove, precipitated, and washed to obtain an analytical sample, whichdid not melt but decomposed slowly between 200.

Anulysis.-Calculated for C H O C, 35.46; H, 5.48; N, 21.77. Found: C,34.77; H, 4.98; N, 21.18.

This corresponds to the following compounds: 1,36- tertiary dibutyoxy2,5,7,10,12,15,17,20,22,25,27,30,32, 35 tetradeeanitro 7,10,17,20,27,30hexazahexatriacontane.

The less soluble portion of the polymer was again treated with dimethylformamide. The material which did not dissolve was removed by filtrationagain treated with dimethyl formamide, and allowed to stand for 9 days.The solid material then remaining, which had a consistency similar to agel, was separated from liquid by centrifuging, and washed with water,ethanol, and ether. turned black at 210-230 after drying in anA-bderhalden pistol.

These intentionally short chained polmers are set out to show thesimplicity of the process of our invention. It is not intended that thepolymers of our invention be limited to the compounds wherein m is alower integer as our process is equally operative in preparing polymerswherein m is 200 or 2,000.

The gelatinous precipitate. Q

The polymer Now having described our invention, what we claim is:wherein R is selected from the group consisting of hy- Comp'ositionshaving the following structural formula: droXy, methoxy, and tertiarybutoxy; R is selected from N0: IITO: N02 IIIOZ III-O2 IITO: *R-OHr-C-CILCHQ-C-CHg-NCHz-CHgNCH2(E-OH3 CHr-C-CH3R I I RI n I the group consistingof hydrogen and hydroxyrnethyl; and I n is an integer ranging from l3.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,040,099 June 19, 1962 Henry Feuer et a1.

It is hereby certified that error appears in the above numbered patentrequiring, correction and that the said Letters Patent should read ascorrected below.

Column 1, line 34, for the radical "-NH read -NO same line 34,immediately following the radical "PO H insert or other phosphoric acidradicals Signed and sealed this 15th day of January 1963.

(SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents

1. COMPOSITIONS HAVING THE FOLLOWING STRUCTURAL FORMULA 